Vehicle emissions standards have become increasingly stringent due to knowledge of the negative environmental effects of hydrocarbon emissions, which are generated by fuel vapors released into the atmosphere. For vehicles and other fuel-operated devices, controlling and containing fuel vapors is important to reduce emissions. Vehicles contain an on-board diagnostic system that monitors whether the fuel system is completely vapor-tight.
The refueling process requires a user to remove a closure, such as a gas cap, which seals a filler tube in the fuel system when the gas cap is screwed over or onto the filler tube. Screwing and unscrewing the gas cap requires the user to undergo several different steps and motions during the refueling process that must either be conducted with two hands or as separate steps (i.e., it is difficult to unscrew a gas cap and hold a refueling nozzle using the same hand at the same time). Currently known structures attempting to solve this problem tend to require the user to apply a high amount of force on the door to open it, making it inconvenient to use.
There is a desire for a structure that can protect an opening in a filler tube from environmental contaminants while allowing the structure to be easily manipulated by the fuel nozzle alone and with relatively low force.